In a mobile communication system, discontinuous reception (DRX) is used as an intermittent reception technique for reducing power consumption of a radio terminal.
A radio terminal in an idle mode can perform a DRX operation to monitor paging at paging reception opportunity (paging occasion) occurring at a predetermined time interval (DRX cycle). Except for the paging reception opportunity, the radio terminal is in a sleep state, and thus the power consumption of the radio terminal is reduced.
In recent years, machine type communication (MTC), in which a radio terminal communicates without intervention of a person in a mobile communication system, has attracted attention. From this background, it is studied to introduce an extended DRX (eDRX) cycle that is longer than the existing DRX cycle so as to further reduce the power consumption of the radio terminal.